Lung Microbiota, Smoking Status, and ARDS Development in Critically Ill Trauma Patients

Cigarette smoking has been associated with ARDS development in multiple settings, but the mechanism of this association is not known. Smoking is associated with changes in the oropharyngeal and nasopharyngeal microbiota, but the impact of smoking on the lung microbiota in critically ill patients has not been studied. We analyzed endotracheal aspirates from critically ill, mechanically ventilated patients after severe blunt trauma at time of ICU admission (n = 74) and 48 hours later (n = 30) to test the hypothesis that exposure to cigarette smoke is associated with an altered respiratory bacterial community composition that may promote subsequent ARDS development. To our knowledge, this is the largest cohort of critically ill patients to undergo deep sequencing of the lung microbiota.